2002 Q45 Code DTC P0505 DEALER CAN"T FIX

[yourhuckleberry1]

ok, here are the steps leading to the error code. Car has been running decent with no codes for the last year . I noticed a 1/4 inch wide 3 inch long crack in the rubber air boot right after the mass flow sensor before the intake. I replaced the boot and notice the butterfly was dirty with fuel tarnish. I removed the entire unit that has the electric throttle control actuator, butterfly and all. I scrubbed it with steel wool and throttle body cleaner spray until it was all clean. After reinstalling everything . The 3rd time driving it threw the code. I can't find any vacuum leaks. The engine seams to be idled up a hair high. What could I have done to the unit with the butterfly/electric throttle control actuator by cleaning it? Your advice is appreciated.

[Q45tech]

Whenever you clean throttle valve the closed idle air can change a tiny [or larger] amount. The system must be relearned per FSM.

[Q451990]

Welcome to NICO!

You can find your factory service manual here http://www.nicoclub.com/FSM/

Look up the DTC you mentioned in section EC. It sends you to a procedure for relearning that involves turning the key on and and pressing the accelerator pedal in a special sequence for it to relearn the opening.

Good luck!

Heath

[yourhuckleberry1]

ok, I am pretty smart, but need some help on the learning procedure. It talks about consult II and being in work support mode. I do have a mac taskmaster scanner. Can I use this to do this procedure or do I not need either?

[Q451990]

There should be two procedures for most things... I'd use the "Without Consult" method.

Heath

[yourhuckleberry1]

ok, I used the " No Consult method", but whenever I go through the process the MIL light never goes out or blinks. It is supposed to start blinking then go out according to the idle air learning process in the service manual (page ec 45) What could be causing this? I have already cleared the codes before I started.

[Q451990]

Is everything warmed up to normal operating temperature before you start the process?

Heath

[SteveTheTech]

In all honesty it make take five, six or more tries to get this right. The timing is critical.

If some one has adjusted the timing using a Consult II you will never be able to reset the idle position.


You should cycle the key on and off at least 5 times and try again.

Make sure all preconditions are met.

Battery voltage: More than 12.9V (At idle)
- Engine coolant temperature: 70 - 99°C (158 - 210°F)
- PNP switch: ON
- Electric load switch: OFF
(Air conditioner, headlamp, rear window defogger)
On vehicles equipped with daytime light systems, set lighting switch to the 1st position to light
only small lamps.
- Steering wheel: Neutral (Straight-ahead position)most important
- Vehicle speed: Stopped
- Transmission: Warmed-up

However it is possible the throttle sensor might be damaged and will require replacement of the throttle to resolve the issue.

If the throttle was forced open (by the plate) the likelihood that the TPS and CTP may be damaged.

Just because I was there anyway here is the procedure.

Without CONSULT-II
NOTE:
-It is better to count the time accurately with a clock.
- It is impossible to switch the diagnostic mode when an accelerator pedal position sensor circuit
has a malfunction.
1. Perform EC-45, "Throttle Valve Closed Position Learning" .

2. Start engine and warm it up to normal operating temperature.

3. Check that all items listed under the topic “PRE-CONDITIONING” (previously mentioned) are in good
order.

4. Turn ignition switch “OFF” and wait at least 10 seconds.

5. Confirm that accelerator pedal is fully released, turn ignition switch “ON” and wait 3 seconds.

6. Repeat the following procedure quickly five times within 5 seconds.
a. Fully depress the accelerator pedal.
b. Fully release the accelerator pedal.

7. Wait 7 seconds, fully depress the accelerator pedal and keep it for approx. 20 seconds until the MIL goes
off.

8. Fully release the accelerator pedal within 3 seconds after the MIL goes off.

9. Start engine and let it idle.

10. Wait 20 seconds.

11. Rev up the engine two or three times and make sure that idle speed and ignition timing are within the
specifications.

12. If idle speed and ignition timing are not within the specification, the result will be incomplete. In this case,find the cause of the problem by referring to the “Diagnostic Procedure” below.

DIAGNOSTIC PROCEDURE
If idle air volume learning cannot be performed successfully, proceed as follows:

1. Check that throttle valve is fully closed.

2. Check PCV valve operation.

3. Check that downstream of throttle valve is free from air leakage.

4. When the above three items check out OK, engine component parts and their installation condition
are questionable. Check and eliminate the cause of the problem.

It is useful to perform EC-138, "TROUBLE DIAGNOSIS - SPECIFICATION VALUE" .

5. If any of the following conditions occur after the engine has started, eliminate the cause of the
problem and perform “Idle air volume learning” all over again:
– Engine stalls.
– Erroneous idle.

[Q451990]

However it is possible the throttle sensor might be damaged and will require replacement of the throttle to resolve the issue. If the throttle was forced open (by the plate) the likelihood that the TPS and CTP may be damaged.

This begs the question... what is the proper method for cleaning Nissan's current style of throttle bodies so as to not damage the sensors?

Heath

[SteveTheTech]

Removal basically,

With the key off and out of the car remove the intake plumbing and the four bolts holding it in places.

The dirty side is the inner side. All you really need to clean it is some spray cleaner. I wouldn't advise the majority of noobs out there to dig into this but if the the risk/rewards work in your favor then...

I spray it off and that's it. Let it dry before reinstalling.

[yourhuckleberry1]

Took the car to dealer. Consult II would not relearn idle and just said please wait and stayed that way. Dealer told me the throttlebody was bad and wanted $1,100 for a new one. I found a used one on a running q45 and installed it. Went back to the dealer and the same thing happened. This car has been fine until I replaced spark plugs with oem's, replaced air filter , replaced pcv valves, and cleaned the throttle body. What could be keeping the consult II from relearning the idle? I have no vacuum leaks and all the settings pre relarn were within spec ( i.e. steering wheel straight, pnp switch :on, engine temp in spec, etc. etc. The dealer has no answser. Thanks for the help.

[SteveTheTech]

and cleaned the throttle body

How?

If you forced open the throttle plate you found your smoking gun.

As for swapping out a KG (known good) part has allot of possible variables to be considered 100%. If there is a pending dtc or altered RAM setting (adjusted base idle). I was resetting the IAVL this past week and was scratching my head until I realized the parking lights were on and the rheostat was set to the brightest possible setting....there are tons of variables and you've got to rule them out.

Did the dealer just leave it at that?
Did you pay them for that?

[yourhuckleberry1]

Dealer has not charged me anything yet, and is looking into possible causes. I appreciate your input.

[jp3.02q45]

Bumping because I'm having the same issue and my local stealership hasn't been very helpful.

I had the battery disconnected overnight because of some other work that I was doing. Before reconnecting the battery, I decided to clean the throttle body and do the relearn procedure from the FSM. I'm able to do the procedure, but I don't think it's completing. Once I've done all the steps, the MIL flashes the sequence for the p0505 code.

Wondering if the OP ever got their issue resolved; and if so, how? I'd be grateful for any other troubleshooting tips anyone might be able to offer, as well.

[SteveTheTech]

Did the dealer tell you you need a new one?

If it was cleaned and the procedure will not complete when performed properly, it is highly likely that solvent worked its way into the motor assembly...ruining it.

[/209JOHN\]

Bump for this thread. I have an 02' f50 with the same issue. Does anyone have any updates on their issues?

[/209JOHN\]

here's what mine TB looked like before I cleaned it.

[life602]

my car has the same issue bu ti think the morons at the dealer might have forced the butterfly on the throttle body/opened it manualy.ohh and thats the same day they broke my intake tube and mine also has a crack but repaired it for temporary time till i can get an used one.my question is how can i trouble shoot the throotlebody to see if thats what happened and if it did is it repairable, i clicked the website to get the dtc' s but was broken but can be my internet but will check again later.

[life602]

ok looked at the link but after i cleared the check engine light it hasnt comeback again and hopefully it wont.but i read that if the car is not idleing normally that the reset step u guys are talking about should be done, so the average rpm is 650 and 700 when on P and mine is pretty off so would this also help reset my idle(just wanna verify) and if the code persists i read the first pages on manuel on ec it says it can be seval things specially when u look under the code P0505 it could just be u are running low on some fluids socheck them as well as the fan which is not runned by a belt or electronically its runned on powersteerin i dont know about ur year but on the 02 it does as well as small air gaps in the intake tube or in throttlebody